1. Field of the Invention
The present invention relates generally to the operation of optical energy producing semiconductor devices such as laser diodes and light emitting diodes, and, more particularly, to a diode biasing circuit that stabilizes the optical output power over a wide temperature range, and method therefor.
2. Description of Related Art
Laser diodes and light emitting diodes (LED) are in present day widespread use both for military applications as well as in the domestic market for use in compact disc players, autofocus cameras, remote control units and intrusion alarms, to name but a few. These diodes exhibit a relatively wide variation in optical output power as a function of temperature. Although for military or space applications the temperature range within which diodes are required to function is larger, even for domestic uses they may have to operate in a range exceeding 0.degree.-50.degree. Celsius (32.degree.-122.degree. Fahrenheit).
Typically, biasing of lasers and LEDs is accomplished by a constant current source. Also, in order to overcome or alleviate the temperature effect where optical power output is desired to be relatively constant, at the present time it is conventional to use feedback circuits which sense any changes in optical power output and adjust the bias current accordingly. Although feedback stabilization bias circuits are effective for maintaining the optical output very precisely, they are relatively expensive and too bulky for many applications.